The street brawler who sparked the friendly-fire killing of an off-duty policeman in White Plains told The Post yesterday that the slain officer never identified himself as a cop and ignored orders to “freeze.”

“I didn’t know who he was,” Andrew Jacobs, 39, who is homeless, said in an exclusive jailhouse interview. “I thought it was a street thing.”

Giving a blow-by-blow of the shooting last Friday, Jacobs said the off-duty officer, Christopher Ridley, flashed his 9 mm Glock and he grabbed for it.

The two wrestled for the pistol, he said, and “the gun fell [then] he pushed me to the ground.”

Police say Ridley, 23, who had been a member of the Mount Vernon police force for two years, was then shot to death by four Westchester County cops who did not know he was an officer.

Jacobs said Ridley never told him he was a cop and never identified himself to the four Westchester cops. He also said Ridley ignored the officers when they shouted “freeze.”

Two eyewitnesses to the shooting supported Jacobs’ account.

Police say Ridley intervened after seeing Jacobs beat up a Bronx man on his way home from work, breaking the man’s wrists and two ribs.

Jacobs is now in the Westchester County Jail after being charged with assault in the attack.

In the interview, he said he is a patient of Westchester’s Mental Health Services Department and has been prescribed the powerful anti-psychotic drug, Haldol, to control his temper. But he said he hasn’t taken it in a month because he doesn’t think he needs it.

Jacobs admitted beating up the Bronx man, who hasn’t been identified, saying he had seen the man talking with a woman Jacobs described as his “girlfriend.”

He said he was getting on a van that takes homeless people from downtown White Plains to a shelter when Ridley grabbed him.

“He said, ‘You’re not going anywhere, yeah,’ ” Jacobs said. “Then he lifted up his shirt and flashed his gun at me. It was in his waistband.”

“I grabbed the gun. We started wrestling.”

The Glock went off twice.

Jacobs said he noticed two cops run out of the nearby county Department of Social Services build- ing and two or three others who were 15 feet away and shouting “freeze.” “The gun was on the ground. He went to pick it up. I was on my back. I thought everyone was going to get shot,” Jacobs said. “He picked up the gun. He started running. That’s when he got shot. It was four to five times.”